1. Technical Field
The present disclosure relates to dimming or dimmer assemblies/modules for controlling lights or loads and, more particularly, to dimmer control assemblies/modules having: (i) an adjustable output response, (ii) enhanced thermal management, (iii) a voltage detector to determine amplitude and zero-crossing, and/or (iv) an estimation of power consumption for multiple loads (e.g., using a single sensor).
2. Background Art
In general, dimming or dimmer modules/assemblies that control dimmable lights or loads are known. For example, some conventional dimmer modules are configured and adapted to control dimmable lights/loads including LED, incandescent and fluorescent, magnetic low-voltage, electronic low-voltage, neon, cold cathode and/or variable speed motors. Dimmer modules are generally useful in a myriad of different environments for residential, commercial and/or industrial applications.
In some conventional assemblies, the dimmer modules are utilized as the lighting (e.g., high-voltage lighting) and/or load control points for a centralized and/or distributed system (e.g., an automation or control system). For example, lights or loads in the centralized system may be wired (e.g., home-run wired) back to a dimmer module, which may be installed and/or housed in an enclosure or the like. The enclosure or the like is typically installed in a mechanical room or electrical closet, and may also house or contain a controller/processor (e.g., an automation system controller/processor).
In general, some of the challenges that arise when creating a dimming module/product can include: (i) implementing an accurate zero-crossing detector, (ii) producing an output that is substantially smooth as the level is adjusted, (iii) providing useful feedback to the user regarding the operating conditions such as power consumption of the loads, and/or (iv) managing the heat that is generated by the dimming modules or dimming circuits.
Some dimmer modules/assemblies for alternating current (AC) loads can generally adjust the output level by turning on power to the load for only a portion of each cycle of the AC supply. The turn-on timing typically should be consistent from cycle to cycle to ensure that the output does not have any substantial detectable variation when set to a specific level. In general, the timing for the turn-on is often referenced to the zero-crossing point of the AC supply. In the case of a lighting control, the method used to detect the zero-crossing typically should be accurate enough to avoid substantial errors in the turn-on that would cause a visibly detectable change in the output. The method should also be robust in the face of noise levels that are sometimes common on the incoming AC supply.
For example, some conventional dimmer modules/assemblies detect the zero-crossing by applying some hardware filtering to the measured line feed and then converting the AC signal to digital pulses by choosing a threshold and then toggling a signal high and low as it crosses the threshold. The timing of the pulses is then typically measured using a microcontroller and further processing can be done with the microcontroller, such as, for example, compensating for delay introduced by the hardware filter, and averaging multiple measurements to create a more stable reference.
Moreover, it typically is a general requirement for high quality dimming controls to provide an output (e.g., light intensity) that varies substantially smoothly during the transition from one output setting to the next. In general, there are three basic issues that affect the smoothness of the dimmer output for lighting controls. First, the human eye typically has a non-linear response to differences in light intensity. Second, the output of some lighting loads is typically not substantially linear with respect to the input power. Third, the output of some lighting loads typically does not change when being dimmed near the high and/or low end of the input signal.
It is noted that some new load types that are becoming common generally have more unusual output characteristics than in the past when controlled by a dimmer module/assembly. Compact-fluorescent lights (CFL) and light-emitting diodes (LED) are examples of these new load types. The output characteristics of these and other loads may have a response that is not able to be adequately corrected for by adding simple curvature to the dimming control signal.
It is also noted that providing certain information about the loads that a dimmer module/assembly controls can generally be useful to the end user. For example, some conventional dimmer modules/assemblies have been adapted and configured to provide an estimate of the power being used by the loads. This may be accomplished by entering the rated power for each connected load into the software that controls the dimmer module/assembly. In general, this data may typically be entered based on the actual loads that were installed when the system was commissioned. The software would then use this information along with the active dim setting on each load to calculate an estimate of the power being consumed.
Furthermore, the circuits that provide dimming control of a load typically generate heat that should be managed so that the assembly/product generally operates at a temperature that does not reach and/or exceed the rated limits of the devices used in the circuit. For example, some primary heat sources are the switching semiconductors that switch the power to the load on and off. Depending on the capacity of the dimmer, the switching semiconductors may generate from a few watts up to tens of watts or more. As an example, some conventional dimming modules typically require that the switching semiconductors generate around about 16 Watts. To manage this heat, a metal heat sink may be incorporated as part of the design. The heat sink typically conducts heat away from the switching semiconductors and generally allows it to more efficiently dissipate into the surrounding environment. Moreover, attaching the semiconductors to the heat sink typically has an effect on the efficiency of the cooling provided by the heat sink.
For example, some various conventional methods have attached the semiconductors to the heat sink. One common method is to use semiconductors that mount perpendicular or vertically with respect to the printed circuit board surface and then screw them to the heat sink. Another conventional method used is to mount the semiconductors parallel or horizontally with respect to the surface of the printed circuit board and then attach the heat sink to the back side of the circuit board. This method typically uses an array of metal-filled holes in the circuit board to conduct heat from the side that the semiconductor is on to the side that the heat sink is on. Additionally, commercial dimmers are typically required by electrical code to be installed inside of an enclosure that is mounted on a wall or recessed into a wall. As such, it is generally desirable to keep the depth of the enclosure to a minimum, so multiple dimmers may be installed one above the other in a vertical enclosure. Some conventional designs utilize perforations on the front of the enclosure so that hot air can generally escape and cool air can enter. Moreover, utilizing fans inside the enclosure is typically unacceptable in most installations, so the enclosure should rely mostly on convective cooling.
Thus, despite efforts to date, a need remains for improved and efficient systems/methods that provide for dimming or dimmer assemblies/modules that control lights or loads. More particularly, a need remains for improved and efficient systems/methods that provide for dimmer control assemblies/modules having: (i) an adjustable output response, (ii) enhanced thermal management, (iii) a voltage detector to determine amplitude and zero-crossing, and/or (iv) an estimation of power consumption for multiple loads (e.g., using a single sensor).
These and other inefficiencies and opportunities for improvement are addressed and/or overcome by the systems, assemblies and methods of the present disclosure.